Habitat constructions, including four biotope ponds, near-natural streams and four artificial floating islands, were performed in a dam lake (Higashi-Arakawa dam lake, Shioya-Cho, Tochigi prefecture) in central Japan. The purpose of these constructions was to improve the dam lake environment as habitat for wildlife. Around these ponds and streams, trees were also planted to improve habitat quality for forest-living species. We chose birds as index of bio-diversity, and monitored them for nearly six years, before and after these constructions. Before habitat creation, the site was a mildly sloped area donimated by annual plants and the area was dominated by ‘openland’ bird species. The monitoring results indicated that both the number of species and birds increased after the habitat creation, and that many wetland and forest birds appeared and used the site for foraging, resting and nesting.

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Factors affecting the number of loggerheads (Carew caretta) landing at the Tokushima coasts were examined from three viewpoints, namely, beach topography changes, annual fishery catch and sea surface temperature (SST). First, it was confirmed that the landing-number of loggerheads evidently decreased atter the construction of detached breakwaters at Gamouda beach. Secondly, it was found that annual fisheryc atches of shellfishes, which are principal foods of loggerheads, and those of seaweeds have positive correlations with the landing-number Subsequently, a multivariate regression model using the fishery catches as explanatory variables was developed. Thirdly, relation between SST in the Pacific Ocean Coast and the landing-number was examineda nd it was clarifiedt hat there is a negativec orrelationb etweent hem. In particular, the increase in SST measured during winter closely relates to the decrease of the landing-number.

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